Add Gson dependency

jme3-templates/nbproject/project.xml

@@ -6,6 +6,14 @@
             <code-name-base>com.jme3.gde.templates</code-name-base>
             <suite-component/>
             <module-dependencies>
+                <dependency>
+                    <code-name-base>com.google.gson</code-name-base>
+                    <build-prerequisite/>
+                    <compile-dependency/>
+                    <run-dependency>
+                        <specification-version>2.8.9</specification-version>
+                    </run-dependency>
+                </dependency>
                 <dependency>
                     <code-name-base>com.jme3.gde.project.baselibs</code-name-base>
                     <run-dependency>